title: Adult nephroblastoma with predominant epithelial component: a differential diagnostic candidate of papillary renal cell carcinoma and metanephric adenoma-report of three cases.
abstract: Although nephroblastoma is the commonest renal tumor of childhood, it is rare in adults. In cases of predominantly epithelial type occurring in adulthood, it might be difficult to distinguish it from papillary renal cell carcinoma and metanephric adenoma. Here, we report three cases of adult epithelial nephroblastoma in 24-, 76-, and 21-year-old females. Histologically, the tumors were composed of papillotubular architectures of small and uniform tumor cells with high nucleocytoplasmic ratio without blastemal element. Immunohistochemically, the tumor cells were positive for WT-1 and CD57 but negative for AMACR, which was helpful to exclude the possibility of papillary renal cell carcinoma. Metanephric adenoma is a benign tumor, which can be distinguished by the observation of the cellular atypism and growth pattern. However, nephroblastoma with predominant epithelial element mimics the malignant counterpart of metanephric adenoma, that is, "metanephric adenocarcinoma."
authors.affiliation: Departments of Diagnostic Pathology, Chiba University Graduate School of Medicine, Chiba 260-8670, Japan.
authors.forename: Shiho
authors.initials: S
authors.lastname: Watanabe
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Naganuma
authors.forename: Michio
authors.initials: M
authors.lastname: Shimizu
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ota
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Murata
authors.forename: Naoki
authors.initials: N
authors.lastname: Nihei
authors.forename: Jun
authors.initials: J
authors.lastname: Matsushima
authors.forename: Shuji
authors.initials: S
authors.lastname: Mikami
authors.forename: Naoto
authors.initials: N
authors.lastname: Kuroda
authors.forename: Yoji
authors.initials: Y
authors.lastname: Nagashima
authors.forename: Yukio
authors.initials: Y
authors.lastname: Nakatani